Despite the potential for use of the chimpanzee in study of human reproductive function and disease, including AIDS, little information is available for the species about epididymal histology, androgen control of epididymal function and the possible role of control of epididymal secretory activity in contraception. Our studies in the intact chimpanzee indicate that epididymal lumenal proteins interact with the surface of sperm and effect their fertilizing capacity. However, the androgen dependence of these epididymal secretory proteins and their biological role in sperm maturation are unknown. It is appropriate, at this time, to continue study in this area in order to maximize the use of the captive chimpanzee population available for research, both from the point of view of scientific investigation and from the point of species conservation. In this application we propose: 1) to complete studies on intact male chimpanzees under conditions of reversible chemical hypophysectomy and castration to identify androgen dependant secretory proteins in the epididymal microenvironment (ADESPs). 2 to isolate those ADESPs which interact with sperm to modify their fertilizing capacity and to generate antibodies against them. 3) to determine which of these antibodies interact with sperm to modify their fertilizing capacity and to use those antibodies to localize, in the epididymis, the sites of synthesis and secretion of associated ADESPs. 4) to generate a cDNA library from a segment of epididymal tissue which synthesize ADESPs and then to screen this library using oligonucleotide and antibody probes to isolate cDNA clones that carry ADESP sequences. These studies will provide significant information on androgen control of epididymal function and of sperm maturation in the chimpanzee. These data are essential for the scientifically responsible use of the chimpanzee as a model for human disease.